Silicon Motion Releases Controllers for USB 3.0 Flash Drives

Earlier this week, Silicon Motion Technology Corp. (Taipei, Taiwan) announced it was sampling single-channel controllers for USB 3.0 flash drives. I asked Robert Fan, VP/general manager for US/EMEA, about the new SM3267 device.

Silicon Motion claims that the controller enables an "industry-leading" data transfer rate of up to 160MB/s read, which is a 30 percent to 50 percent improvement from most single-channel USB 3.0 flash drive controllers in the market today. (The controller is also specified with a 60MB/s write rate.) Fan explains that the performance claims are based on the company’s internal testing as compared to commercially available USB 3.0 flash drives available today. This is one of those challenging specs to compare among devices, because the performance depends greatly upon the drive used.

The company backs up its claim to cost effectiveness with integration. Specifically, Fan says this integration includes a crystal oscillator, a 5V to 3.3V low dropout oscillator (LDO) and a 5V to 1.2V DC-DC converter. Though he wouldn’t reveal the controller’s cost, Fan said “the integration of the above components enable customers to save 15 percent to 20 percent of their BOM cost.”

So what is most noteworthy about this product? The SM3267 controller uses a single-channel architecture that supports interleaving up to four flash devices. The controller also supports high speed toggle NAND and DDR NAND interfaces.

In the press materials, Wallace Kou, president and CEO of Silicon Motion, announced that the company had received design-ins from most of its current USB controller customers. So, he expects to see SM3267-based USB 3.0 flash drives to become commercially available starting in the fourth quarter of 2013. The product supports most NAND flash, including 2y/1x/1y nm TLC, MLC, high-speed Toggle, and ONFI DDR NAND manufactured by Samsung, Toshiba, SanDisk, SK Hynix, Micron, and Intel. Available in chip-on-board (COB) and in a 48-pin QFN green package, it has passed USB-IF compliance testing and WHCK (Windows Hardware Certification Kit) tests for Windows 7 and Windows 8.

USB flash needs to get past the "floppy replacement" market, where single-threaded bandwidth is the main metric to brag about. UASP lets a USB3 drive handle multiple transactions, and makes it far more realistic to replace a normal (eg SATA) disk - it hasn't been a bandwidth issue for years. Does this controller support UASP?